1. Field of the Invention
The present invention relates, in general, to a capacitance compensation circuit, and, more particularly, to a continuous-time circuit and method for compensating a polynomial voltage-dependent characteristic of a capacitor.
2. Relevant Background
Input-dependent capacitance constitutes one of the main limitations to the ideality of a radio-frequency (RF) as well as of an analog precision front-end. In fact, traditionally even necessary structures such as Electro-Static Discharge (ESD) protection diodes and other clamping circuitry have been minimized at the very input of those circuits, to try and mitigate the distortion effects caused by input-dependent capacitance. While the solution of minimizing the input structures may lessen the undesirable effect of input-dependent capacitance, it is not always practical depending on the specific application, nor does it substantially eliminate distortion. For extremely high precision circuits targeting 100 dB of dynamic range and higher, even the small amount of remaining input-dependent capacitance must be addressed. Thus, a need remains for a compensation circuit that can be adjusted to correct for the voltage-dependency in an input capacitor.